Process of redistillation of products resulting from destructive distillation of resinous wood.



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:cARoLINA; e CORPORATION or NOE-TH CAROLIN :frnocnss or nnms'rrrra'rroivor rnonucrsgammanrs'rrrrarrou or ansmouswoon,

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To al l whom it may concern:

Be it known that we, HAR LD CHAsEj; anctJoHX L. GRA FL'IN, citizens forthe modification of the broad pr United States, residing atlVilmington,in

the county. of New Hanover, State of North used to heat themateiCarolina, have invented certain new and usefulImprovements in Processesof Redis--' tillation'of Products Resulting from Detructive Distillationof Resinous WVood, of which the following is a description.

Our invention relates to a process of redistillation of productsproduced from resinous woods by destructive distillation, and

has for its object to produce from such products, which are necessarilyso characterized by creosote odor or tarry odor and by heavy residualmatter, as to render them incapable of use except for preserving wood orother material and other uses in which their odor is not objectionable,-oils which are clear, viscid, free from creosote or creosote odor andcapable of use for purposes such as those for which so-called rosin oilis used.

.By subjecting these products, such as creosote oil, pitch and tar, ormixtures thereof,-

to redistillation 'at a temperaturenot above 500 degrees Fahrenheit alight creosote -.oil may be driven off which carries all of the creosoteodor, and by then further distilling at a higher temperature, notover.700 deoitwhich is free from creosote odor and re sembles rosin oilin appearance and characteristics, and which is of relatively high valuecompared with the market value of the creosote oil or pitch or tar. Thisprocess is not broadly claimed herein, being the subject-matter of aseparate application forpatent filed by us under date of April 17,

1915, Serial No. 22,030.

. We have discovered that by using super heated steam blown directlyinto and through the contents of the still or retort to effect thedistillation, either with or without the use of heat from other sourcesapplied to the exterior of the retort or otherwise, the light creosoteoil may be driven off at a much lower temperature than can be done wherethe contents of the retort are treated without the use of the steam, andin driving oil the clear, viscid oil the use .of

superheated steam makes it possible to ac- Hiinorarour. cHAsE ANDJOHNGRAFFLIN, or 'WILMlINGTDN4 assreuoras TO- NATIONAL-ween nIsTrL-LmcooMrAivY,-or WI ap n'cationmea April 17, 1915; Seria1No.22,031.

complish this at a o otherwise possible.

O nt-c invention 0 IlS'ISfiS wood creosote oil, pitch or tar, or anyprodnot containing any of these substances, into a still or retort,which may be of any usual construction, but which is preferably providedwith heating means capable of regulation so as to heat the contents ofthe still or retort to a predeterminedtemperature and maintain suchcontents at suchtemperature, and is also provided with a pipe leadinginto it, through which sup'erhe'ate'd'steam may be blown into andthroughthe contents of the still. The still or retort being properly chargedthe superheated steam is turned on and the distillation process begins.The contents of the still or retort being heated by the'superheatedsteam, either' with. or without additional heat applied to the eX-terior of the still or retort or otherwise, to a temperature notexceeding 390 degrees Fahrenheit, a light creosote oil is driven off. Bymaintaining the heat for a suitable length of time all of this lightcreosote oil contained in the material in the still or retort may bedriven ofi without raising the temperature above 390 degrees, the amountof light, creosote oil driven 011' depending on the character of thecontents of the still or retort, the amount being comparatively small ifthe contents of the still or retort consist wholly or mainly of pitch ortar and comparatii'ely large if the contents consist wholly or,largelyof creosote oil. The initial temperature required will also varysomewhat with the character of the contents of the still or retort, thedrawing 05 of the light creosote oil beginning at a lower temperaturewhen the contents are made up wholly or largely of creosote oil thanwhen they consist largely of pitch or tar. And

the same is true in the drawing ofi' of the clear, viscid oil, the heatrequired being less when the proportion of creosote oil in the originalcharge greater.

After the light creosote oil has been driven ofi', the contents 'of thestill is raised by the superheated steam either with or withoutadditional heat applied to the exterior of its retort or still orotherwise, 'to a temperature not exceeding 500 F during which periodofthe process, a large proportion of the remaining contents of the stillis driven off as a clear viscid oil, leaving a comparatively snialli'esidue.

ucts to a temperature not exceeding 390' degrees Fahrenheit, by forcingsuperheated steam through them until all substances havmg -a creosoteodor have been driven off,

raising the remainder to a temperature to 1.1e2,ose

not exceeding 500 degrees ,Fahrenheit and Which'consists in heating suchproducts to a temperature not exceeding 390 degrees Fahrenheit byforcing superheated steam through them and by applying other heat tothem, maintaining them at such temperature until all substances having acreosote odor are driven off, raising the remainder to a temperature notexceding 500 degrees Fahrenheit and forcing superheated steam throughsuch remainder to distil oil? oil free from creosote odor.

This specification signed and witnessed this 18th day of May A. D. 1914.

HAROLD M. CHASE. JOHN L. GRAFFLIN.

I In the presence of-- C. B. HARRiss, M. I. HARRISS,

